Recovering the Tricolored Blackbird in California

Abstract

The Tricolored Blackbird (hereafter, also “tricolor”) is a near-endemic California passerine that forms the largest colonies of any North American landbird since the extinction of the passenger pigeon (Ectopistes migratorius) over 100 years ago (Beedy and Hamilton 1999). Tricolor numbers have plummeted recently, from an estimated 395,000 birds in 2008 (Kelsey 2008) to 145,000 in 2014 (Meese 2014) due to a variety of factors including widespread nesting and foraging habitat losses to agriculture and urbanization, destruction of nesting colonies during the routine harvest of their grain field nesting substrates and shooting in autumn in paddies of ripening rice. This decline in abundance coincided with a period of chronically low reproductive success (Meese 2013), and led, in December 2014, to an emergency listing as an endangered species under the California Endangered Species Act (CESA).